cdrdao (WAS Re: [CLUE-Tech] ISO images from Audio CD's?)

[Timothy C. Klein]

* David Anselmi (anselmi at americanisp.net) wrote:
> Timothy C. Klein wrote:
> [...]
> 
> >If you don't want a drive to be a generic SCSI, (like, say, my DVD drive, 
> >which has its performance
> >destroyed by the software only sg driver), you can't use that drive as a 
> >read device.
> 
> Why?  Can't you just change out the drivers (assuming they are all 
> modules)?  True, you can't write to it as a CDRW and read from it as a 
> DVD at the same time...
> 

Because, to simplify the job of the burning software, it only
understands SCSI commands.  So, as far as I know, it started with
cdrecord.  Only devices that have a SCSI interface can be used by
cdrecord.  So, if you wanted to pipe information from one CD into
cdrecord and right back out to another CD, cdrecord can only read from
a CD drive if it speaks SCSI.  So, if it an IDE device, cdrecord
won't/can't talk to it.  This is not usually a big deal, unless you have
some reason to get data off of the drive quickly, and thus want a driver
that understands the hardware, ergo, a DVD that needs to get many
megabits from the drive per second in order to show a decent frame rate
for movies.  So I can only use by DVD as a read device for my CD burner
if I have it as IDE-SCSI, but that makes it unusable for movies.

Now, since a lot of burning software relies on cdrecord, this dependency
has propagated.  And some new, seemingly unrelated software has popped
up with the same dependency.  So for any CD burning type purpose, even
if the drive is used only for reading, you have to have a real SCSI
device, or use the SCSI-emulation features of ATAPI drives.  Cdparanoi,
apparently cdrdao, are two that don't seem to rely on cdrecord, but have
this same restriction.

If anyone can prove me a liar, I would be very interested.  I find the
restriction a bit annoying (but again, I sympathize with the developers).

Tim
--
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== Timothy Klein || teece at silverklein.net   ==
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== "Hello, World" 17 Errors, 31 Warnings... ==
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